Flight modes (Stabilize, AltHold, Loiter, Auto) in Drone Programming - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the Stabilize flight mode?

Stabilize mode lets the pilot control the drone manually while the system helps keep it level and stable. It does not hold altitude or position automatically.

beginner

How does AltHold mode assist the pilot?

AltHold mode keeps the drone at a fixed altitude automatically, so the pilot only needs to control horizontal movement and direction.

intermediate

Describe the Loiter flight mode.

Loiter mode holds the drone's position and altitude using GPS. The drone stays in place even if the pilot releases the controls.

intermediate

What happens in Auto flight mode?

Auto mode lets the drone follow a pre-programmed mission or path automatically without pilot input.

beginner

Which flight mode would you use to keep the drone hovering at a fixed spot without manual control?

Loiter mode is used to keep the drone hovering at a fixed position and altitude automatically.

Which flight mode helps keep the drone level but requires manual control for altitude and position?

A Loiter

B Stabilize

C AltHold

D Auto

Stabilize mode assists with leveling but does not hold altitude or position automatically.

In which mode does the drone maintain a fixed altitude automatically?

A AltHold

B Auto

C Loiter

D Stabilize

AltHold mode keeps the drone at a set altitude without pilot input on vertical movement.

Which flight mode uses GPS to hold the drone's position and altitude?

A Loiter

B AltHold

C Stabilize

D Auto

Loiter mode uses GPS to keep the drone in one place automatically.

What does Auto mode allow the drone to do?

A Hover in place manually

B Stabilize manually

C Maintain altitude only

D Follow a pre-set mission automatically

Auto mode runs a programmed mission without pilot control.

If you want to fly the drone manually but with help to keep it level, which mode should you choose?

A Auto

B Loiter

C Stabilize

D AltHold

Stabilize mode helps keep the drone level while you control it manually.

Explain the main differences between Stabilize, AltHold, Loiter, and Auto flight modes.

Think about how much control the pilot has in each mode and what the drone does automatically.

When would you choose Loiter mode over AltHold mode during a drone flight?

Consider if you want the drone to stay still in the air or just keep the same height.

Practice

1. Which flight mode allows the pilot to manually control the drone's attitude and throttle without automatic stabilization?

easy

A. Auto mode

B. Stabilize mode

C. Loiter mode

D. AltHold mode

Solution

1. Step 1: Understand Stabilize mode function

   Stabilize mode lets the pilot control the drone manually, with basic stabilization but no automatic altitude hold.

2. Step 2: Compare with other modes

   AltHold holds altitude automatically, Loiter holds position, and Auto runs pre-programmed missions.

3. Final Answer:

   Stabilize mode -> Option B

4. Quick Check:

   Manual control = Stabilize mode [OK]

Hint: Manual flying without altitude hold is Stabilize mode [OK]

Common Mistakes:

• Confusing AltHold with Stabilize
• Thinking Loiter allows manual control
• Assuming Auto mode is manual

2. Which of the following is the correct way to set the drone to AltHold mode in code?

easy

A. set_mode('Loiter')

B. set_mode('Auto')

C. set_mode('AltHold')

D. set_mode('Stabilize')

Solution

1. Step 1: Identify the function to set mode

   The function set_mode() is used to change the drone's flight mode by passing the mode name as a string.

2. Step 2: Match the mode name for altitude hold

   To hold altitude automatically, the mode name must be 'AltHold'.

3. Final Answer:

   set_mode('AltHold') -> Option C

4. Quick Check:

   Altitude hold mode = 'AltHold' string [OK]

Hint: Use exact mode name string 'AltHold' in set_mode() [OK]

Common Mistakes:

• Using wrong mode string like 'Auto' or 'Loiter'
• Misspelling mode names
• Passing mode as variable instead of string

3. What will be the output of this code snippet?

mode = 'Loiter'
if mode == 'Stabilize':
    print('Manual control active')
elif mode == 'AltHold':
    print('Altitude hold active')
elif mode == 'Loiter':
    print('Position hold active')
else:
    print('Automatic mission active')

medium

A. Position hold active

B. Altitude hold active

C. Manual control active

D. Automatic mission active

Solution

1. Step 1: Check the value of mode variable

   The variable mode is set to 'Loiter'.

2. Step 2: Follow the if-elif conditions

   The code checks if mode equals 'Stabilize' or 'AltHold' first, which it does not. Then it checks if mode equals 'Loiter', which is true, so it prints 'Position hold active'.

3. Final Answer:

   Position hold active -> Option A

4. Quick Check:

   mode == 'Loiter' prints 'Position hold active' [OK]

Hint: Match variable value with if-elif conditions carefully [OK]

Common Mistakes:

• Choosing first if condition without checking value
• Confusing Loiter with Auto mode output
• Ignoring else block

4. Identify the error in this code snippet that tries to switch to Auto mode:

def switch_mode(mode):
    if mode = 'Auto':
        print('Auto mode activated')
    else:
        print('Other mode')

medium

A. SyntaxError: '=' used instead of '==' in if condition

B. RuntimeError: mode variable undefined

C. Logical error: should use '!=' instead of '='

D. No error, code runs fine

Solution

1. Step 1: Check the if condition syntax

   The condition uses a single '=' which is assignment, not comparison. This causes a syntax error in Python.

2. Step 2: Correct the condition to use '==' for comparison

   Changing '=' to '==' fixes the syntax and allows proper comparison.

3. Final Answer:

   SyntaxError: '=' used instead of '==' in if condition -> Option A

4. Quick Check:

   Use '==' for comparisons, '=' is assignment [OK]

Hint: Use '==' in if conditions, '=' is for assignment [OK]

Common Mistakes:

• Using '=' instead of '==' in conditions
• Confusing assignment with comparison
• Ignoring syntax errors

5. You want the drone to automatically fly a mission but keep altitude stable if GPS signal is lost. Which mode combination should your program switch between?

hard

A. Stabilize mode for mission, switch to Auto if GPS lost

B. Loiter mode for mission, switch to Stabilize if GPS lost

C. AltHold mode for mission, switch to Loiter if GPS lost

D. Auto mode for mission, switch to AltHold if GPS lost

Solution

1. Step 1: Understand mission and GPS loss handling

   Auto mode runs the mission automatically. If GPS is lost, the drone cannot continue Auto mode safely.

2. Step 2: Choose AltHold to maintain altitude during GPS loss

   AltHold keeps altitude stable without GPS, preventing sudden drops.

3. Final Answer:

   Auto mode for mission, switch to AltHold if GPS lost -> Option D

4. Quick Check:

   Auto + AltHold for GPS loss safety [OK]

Hint: Auto for mission, AltHold to keep altitude if GPS fails [OK]

Common Mistakes:

• Using Stabilize during GPS loss risking altitude drop
• Confusing Loiter with mission mode
• Not switching modes on GPS loss